Amc-XT-tun-sm维修电路原理图.pdf

STEREO TUNER RadioFans.CN 收音机爱 好者资料库 TUNER ALIGNMENT PROCEDURE FM SECTION A. PREPARATION 1. Set stereo modulator to mono mode with 1KHz modulating signal unless otherwise state. 2. Set signal generator to FM mode with 75KHz deviation. 3. Store the following frequencies: 87.5MHz, 90.1MHz, 98.1MHz, 106.1MHz and 107.9MHz. 4. RF levels are open circuit voltages of signal generator with 75 ohms output impedance. B. OSCILLATOR TUNING VOLTAGE 1. Connect DVM between FE1 No. 5 PIN and ground. 2. Tune to 87.5MHz and check DVM for reading of 3Vdc +/-0.5Vdc 3. Tune to 107.9MHz and check DVM for reading of 20.5Vdc +/-0.5Vdc. If either of the above is out of tolerance, adjust FE1 (oscillator coil L101) until both readings are within tolerance. C. I.F. 1. Connect DVM between TP2 and TP3. 2. Apply 98.1MHz (60dBu) to FM antenna input and tune to 98.1MHz. 3. Adjust IFT1 (FM IF) for 0Vdc +/-50mV reading on DVM. 4. Adjust IFT2 (FM IF) until minimum THD is achieved at audio output. 5. Repeat (3) and (4) until no further improvement can be made. D. FRONT-END I.F. 1. Apply 98.1MHz (12dBu) to antenna input and tune to 98.1MHz. 2. Carefully adjust FE1 IFT until minimum THD is achieved at audio output. E. R.F. 1. Apply 98.1MHz (7dBu) to antenna input and tune to 98.1MHz. 2. Check if THD is better than 3%. If not, proceed to (3). 3. Adjust FRONT-END COILS (L102 - L104) by squeezing or stretching using a non-metallic tool until THD is better than 3%. 4. Check THD at 90.1MHz and 106.1MHz with 8dBu input. If THD is more than 3% for both frequencies, re-adjust until required THD is met. F. AUTOSEARCH AND FM STEREO LEVEL 1. Turn VR2 fully clockwise. 2. Set stereo modulator to L=R mode and 98.1MHz (32dB) to antenna input. 3. Adjust VR2 clockwise until “S” light up in the LCD. RadioFans.CN 收音机爱 好者资料库 4. Check if auto-search operation is working properly at antenna input level of 28dB. G. CENTER TUNER LED 1. Turn VR1 fully clockwise. 2. Set stereo modulator to MONO mode and 98.1MHz (26dB) to antenna input. 3. Adjust VR2 clockwise until “I” display in the LCD. H. STEREO SEPARATION AND PILOT SUPPRESSION 1. Modulate L- only at 98.1MHz (68dBu) and adjust VR3 for minimum output on right channel. 2. Modulate R- only and adjust VR3 for minimum output on left channel. 3. Repeat (1) and (2) until readings are the same and within specification (45dB). 4. Turn off modulating signal but leave pilot tone. 5. Adjust FL6 and FL7 for minimum output on left and right channels, respectively. AM SECTION A. PREPARATION 1. Set signal generator to AM mode with 1KHz at 30% modulation. 2. Connect 22pF ceramic capacitor between signal generator and AM antenna input terminal input; the capacitor should be as close as possible to antenna input terminal. 3. Store the following frequencies: 600KHz, 1000KHz and 1400KHz. B. OSCILLATOR TUNING VOLTAGE 1. Connect DVM between TP4 and TP5 (Ground). 2. Tune to 600KHz and adjust L4 (AM OSC) for 1.75Vdc +/-50mV reading on DVM. C. I.F. 1. Apply 1000KHz (45dBu) to antenna input. 2. Tune to 1000KHz and adjust IFT3 (AM IFT) for maximum reading on audio output. D. R.F. 1. Apply 600KHz (45dBu) to antenna input. 2. Tune to 600KHz and adjust L3 (AM ANT) for maximum reading on audio output. 3. Apply 1400KHz (45dBu) to antenna input. 4. Tune to 1400KHz and adjust C26 (VC TRIM) for maximum reading on audio output. 5. Repeat (1) to (4) until no further improvement can be made. ITEM PART NUMBERLOCATIONQTY 1 90-1742-2MODULE, TUNER MAIN PCBXT1 2 29R-1236-220L5.6.INDUCTOR 22uH 10% SMD 12102 3 29R-1236-2R2L1.INDUCTOR 2u2H 10% SMD 12101 4 29R-1236-680L2.INDUCTOR 68uH 10% SMD 12101 5 30R-LC72131MIC4.IC FREQ SYNTHESIZER LC72131MMFP20 RoHS SANYO1 6 30R-MMBD4148D5.6.8.12.13.14DIODE SWITCHING MMBD4148/914DIODE 0.2A/75V SOT-236 7 30R-MMBT4401LT1Q1.10.11.12.14.15.19.20.26.TR NPN MMBT4401LT1ON 0.6A/40V SOT-239 8 30R-MMBT4403LT1Q9.13.25TR PNP MMBT4403LT1ON 0.6A/40V SOT-233 9 30R-M4D9.10.11RECTIFIER DIODE M41A 400V SMA WILLAS3 10 30R-AT32L-8AUIC9.IC ATMEGA32L-8AU 8-BIT AVR8K FLASH TQFP 44A 1 11 30R-2SC1815GRQ2.3.TR NPN 2SC1815GR TAP TOSHIBA2 12 30R-2SC829CQ4.5.6.7.8.TR NPN 2SC829C TO-92 TAP5 13 30R-J112Q16.17.18.TR JFET N-ch J112 35V 350mWXT TO-92 ON/FAIRCHILD3 14 17R-2019C26.VC TRIM 30PF TZ03R300FR 1 15 16R-1AN121JR97.RES MO 120R 5% 1W RSF1 MK 1 16 29R-R6V104BVR2.3.SEMI-FIX VR 100KB RH0615C15J2 17 30R-4020X1.CER-RESONATOR CSB456F11 1 18 30R-4017-1X2.CRYSTAL QUARTZ 7.2MHz HC-49US1 19 15R-3010*AFEI.FRONT END KST-F724HA-1 1 20 17R-2016-1FL4.CERAMIC FILTER SFZ450B 1 21 17R-2017FL5.EMI FILTER S-174-077 1 22 17R-2027FL1.2.CERAMIC FILTER 10.7MHz REDMURATA SFELF10M7FA00-B03 23 29R-1224IFT2.FM IFT TWS-384-0428(4400) 1 24 29R-1225IFT3.AM IFT TWS-384-0425(5200) 1 25 29R-1226IFT1.FM IFT TWS-384-0427(4300) 1 26 29R-1228FL6.7.MPX FILTER S-174-084 10DFEE012 27 29R-1230L3.AM RF TWS-384-426 (M-10BLN)TUNER SERIES SUMIDA1 28 29R-1231L4.AM OSC TWS-384-424 1 29 30R-1N60*AD1.2.DIODE 1N60 (RED) 2 30 30R-LA1266IC1.IC LA1266 (AM/FM IF) 1 31 30R-LA3401IC2.IC LA3401 (FM MPX) 1 32 30R-M51951BIC6.IC RESET M51951BSL MITSUBISHI1 33 30R-SVC321SPAD3.4.DIODE SVC321SPA(A) 2 34 12R-2154-1J7.JACK RCA 2P SEMI GOLD PLATEDDTR-0202G-004-11 35 12R-2240J1.ANT TERMINAL AJ-2019-040 USXT 1 36 17R-2.5EF228MC89.90CAP EL 2200uF/25V 20% HTC5 13x21mm2 37 17R-2023-1FL4.BAND PASS FILTER LPF88A 1 38 30R-HIN232CPIC5.IC RS232 DRIVER/RECEIVERHIN232CP DIP16 RoHS XT1 39 30R-LM7805AIC9.IC POSITIVE VOL.REG.LM7805(F)ANS/JRC/ST/IR/ON 1A/5V TO-2201 40 30R-LM7812AIC10.IC POSITIVE VOL.REG.LM7812(F)ANS/JRC/ST/IR/ON 1A/12V TO-2201 41 30R-LM7912AIC11.IC NEGATIVE VOL.REG.LM7912(F)ANS/JRC/ST/IR/ON 1A/-12V TO-2201 42 30R-MPS6724Q21.TRANSISTOR MPS6724 1 43 30R-RB154BD1.DIODE BRIDGE RB154 1.5A/400V1 44 31R-1383SW2.SWITCH SLIDE SKV-22D21-G6-TA2P2T L=6mm 1 45 31R-1383-1SW1.SWITCH SLIDE SKV-24D02-G6-NA2P4T L=6mm XT1 46 35R-3046RL1.RELAY DPST 12V UL/CSA/VDEVB-12MBU-5 TAKAMISAWA1 47 90-1798MODULE, TUNER DISPLAY XT1 48 19R-1798PCB FR4 D-S DISPLAY XT1 49 30R-MMBD4148D1.2.3.4.5.DIODE SWITCHING MMBD4148/914MZC&M DIODE 0.2A/75V SOT-235 50 30R-SAA6588TU100.IC RDS PRE-PROCESSOR SAA6588TSO20 PHILIPS 1 51 30R-PT2222-001U101.IC RC TRANSMITTER PT2222-001SOP24 PRINCETON1 52 29R-1242L1.FERRITE BEAD 1.0A 0805 ACM201209A6001 53 30R-2SD1781KRQ1.TR NPN 2SD1781KR SOT-23 1 54 30R-M4D15.RECTIFIER DIODE M4MZC-66 1A 400V SMA WILLAS1 55 30R-MIR053LED1.DIODE INFRARED EMITTINGMIR053 XT1 56 30R-4028-1X1.CRYSTAL 4.332MHz HC-49US 1 57 30R-4029X2.RESONATOR CSB455EB MURATA1 58 30R-1156*BLCD1.LCD MODULE C1624MWLJ1 16x2ECOMAG w85xh30 xd13.2mm1 59 30-PIC-26043TH2IR1.RECEIVER IR T7a PIC-26043TH21 60 31R-1365 S41-52.55.56.33.60.TACT SW SKHHBV2710-EK 7mm 6 61 31R-1375TIME/TEXT/PROGRAM/TYPE. SWITCH TACT 4.5x6.5mm L=17mmKA-170 RoHS TECX4 62 12R-2239-1J3.J4.JACK DC POWER 2.5mm DJ-0702B-025 JYE TAI2 63 31R-1383SW3.SWITCH SLIDE SKV-22D21-G6-TA2P2T L=6mm 1 64 90-1801MODULE, POWER SUPPLY XT1 65 19R-1801PCB FR4 D-S POWER SUPPLY RoHSXT1 66 31R-1250SWITCH PUSH NON-LOCK 1P RoHSXT/AV81HT1 XT SERVICE PART LIST - EC, BLACK PART DESCRIPTION 67 XT-B-COMCOMMON PARTSXT1 68 11R-8644*APANEL REAR RoHSXT1 69 11R-8633B-2PANEL FRONT BLACKXT w430 xh72xd23mm1 70 11R-6425-1CHASSIS FRONT RoHSXT 420 x57.2x13.5mm1 71 11R-6436CHASSIS MAIN RoHSXT1 72 13-1063WINDOW DISPLAY XT1 73 11R-1123-1COVER TOP BLK RoHSAMC1 74 12-1083POWER LINK1 75 12R-1120 SHAFT BUTTON 6 76 12R-2177ANT FM 300 ohm T TYPE1 77 12R-2178ANT FM BALUN AJ-2010 A175 ohm 300 ohm1 78 12R-2116*BAC INLET 3P W/FUSE HOLDER SC-8F-21C 10A/250V SWEETA1 79 12R-3110 KNOB PUSH BLK 6 80 12R-3152GNPOWER SW BUTTON GREEN AMC1 81 13R-8227BPOWER KNOB BUSHION AMC1 82 28R-1046-1BFOOT (R) H=17mm BLK AMC2 83 28R-1046-2BFOOT (L) H=17mm BLK AMC2 84 29R-2185*B-UNTRANSFORMER POWER XT1 85 29R-3071RF CORE FILTER 1 86 30R-1148LED 3mm BLUE M034BLD GAN/SIC 430nM PD=100mW VF=3.5V1 87 31R-1376SWITCH SLIDE 115/230V EV-12-2 DPDT UL/VDE1 88 21R-2622-1*AMANUAL INSTRUCTION RS2321 89 XT-B-ECEC VER PARTS 230V1 90 14R-5030*APOWER CORD EC 3P 1.83M BLKEL211+EL701 H05VV-F 0.75/3C1 91 CTR-5264CARTON INNER RoHSAMC w494xd361xh143mm1 92 CTR-5265CARTON OUTER RoHSAMC w506xd373xh664mm0.25 93 R32S1250500TUSFUSE UTE T500mA/250V RoHST-LAG (UL/CSA/VDE) 5x20mm2 94 R32S12502K0TUSPFUSE UTE T2A/250V RoHST-LAG (UL/CSA/VDE/PSE) 5x20mm1 PART NUMBERXT-B_ECXT-B_A1XT-S_EC 11-1123S-1 11R-1123-111- 11R-8633B-211- 11R-8633S-2-1 12-3122S-16 12R-3097S-1 12R-31101616- 12R-3152GN11- 14R-5030*A1-1 14R-5107*B-1- 15R-2090B44- 15R-2090S-4 16R-1:2CA275J-1- 21-30243-3 21R-2315-1- 21R-2331-A1-1- 21R-2331-EC1-1 21R-2332-A1-0.5- 21R-2332-EC0.5-0.5 21R-24401-1 21R-3015-1-1- XT DIFFERENT VERSION PART LIST